Pipe bender



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PIPE BENDER Filed July 25, 1942 2 Sheets-Sheet 2 m Il A II Il' lI Il rames my s, 194s IPWE RENDE@ iegmund Mandi, Itiiiwaukec, Win., assigner to Blackhawk Mfg. Co.. Milwaukee, Wis., a corporation of Wisconsin amusants any es, iste, anni ne. man? Y (ci. its-ac) The present invention relates generally to ixnprovernents in the art of longitudinally bending elongated elements, and especially relatively thin walled tubes or pipes. to definite or predetermined curvature and without distorting the crosssectional shapes of the hollow elements during the bending operations.

An object-of the .invention is to provide a new and useful tube or pipe bender which is simple in construction and emcient in operation.

Many different types of tube or pipe benders have heretofore been proposed and used with varying degrees oi success, and in some of these prior devices hydraulic pressure was utilized to actuate the mechanisms and the units were of a relatively portable nature. n one oi these prior portable hydraulic pipe benders, links having rollers journalled in their outer ends, were pivotally suspended from the cylinder of a hydraulic ram, and the piston of this ram had a segment pivotally attached thereto and disposed between the links and rollers. This segment was provided with a curved pipe bending surface formed eccentrically with respect to its supporting pivot, and the portions of the segment adjacent to the curved pipe engaging surface were adapted to roll in direct contact with a rectilinear follow bar which also engaged the pipe and advanced along the rollers during each bending operation. The lengths of pipe were gripped by a clamp carried by the segment near one end of the curved surtubing to desired curvatures with minimum distortion of the cross-sectional shape of the tubes.

A further specific object of this invention is to provide a sturdy and compact hydraulically actuated portable pipe bender, wherein the bending force is most effectively applied to the Work with minimum friction loss.

Still another specific objeetxof my invention is to provide a strong and panerinl pipe bending device operable by means of a relatively small hydraulic ram and in any desired position, and which can be manufactured and sold at moderate cost.

These and other objects and'advantages of the n invention will be apparent from the following detailed description.

A clear conception of the features constituting the present improvement, and of several typical embodiments of the invention in commercial pipe benders, may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. l is a side elevation of a hydraulically actuated pipe bender equipped with a bender segment for small diameter pipe, portions of the assemblage having been broken away:

Fig. 2'is an end view of the pipe bending unit of Fig, 1;-

Fig. 3 is a fragmentary end view of a similar 'pipe bending assemblage, equipped with a rotary rigid follower instead of a bar follower as in Figs. l. and 2; f

Fig. 4 is a side elevation of a somewhat modied hydraulically actuated pipe bender equipped with a bending segment for large diameter pipe;

Fig. 5 is a fragmentary end view of the bending unit of Fig. d; and

Fig. 6 is a fragmentary end view similar to that 4of Fig. 3, but equipped with a rotary resilient or .unnecessarily restrict the scope or utility of the improvement.

Referring especially to Figs. 1 and 2 of the drawings, the improved hydraulically actuated portable pipe bender shown therein, comprises in general, a rigid frame 8 having a threaded socket 9 at one end and a bearing or reaction .roller ill journalled for rotation on a transverse pinil detachably secured to its opposite end,

.and also having a series of alined sets of holes i2, i2', i2 formed in the medial frame portion -with the axes of the holes out of the common plane of the axes of the socket t and pin ii; a

pipe bending `member or segment i3 swingableupon a transverse pivot pin I4 which is detachably and interchangeably co-operable with the holes I2 of any of the three sets, and having an arcuate pipe engaging groove or surface Il formed concentric with the axis of the pin I4 the vgroove surface IB; a U-shaped pipe gripping element or clamp I1 pivotaliy secured to the segment I3 near one end of the surface Il and ilanges I t by means of a pin I 31; an elongated rectilinear follow bar or follower I9 having straight pipe engaging grooves 20, 2i of different curvature in the opposite sides thereof, one of which is col-operable with aV pipe held by the clamp I1 while the opposite face of the bar is simultaneously co-operable with and movable along the bearing roller I an anti-friction roller 22 journalled for rotation upon a pin 23 secured to the segment I9 between the pivot pin I4 and the groove surface Il. remote from/the clamp I1; and a hydraulic ram having a cylinder 24 nxedly but detachably-secured to the socket l, and also having a reciprocable plunger member or piston slidable within the cylinder 24 and provided with a fiat face 23 loosely engageable with the roller 22 and across which the latter is adapted to ride. t

The rigid frame may either be formed of one piece by casting, or of several pieces firmly united by welding, and this frame should be of durable construction in order to withstand the stresses to which it is normally subjected. Although the bearing roller I0 is readily removable from the frame 3 upon withdrawal of its Journal pin II, such removal is not necessary even when adapting the pipe bending mechanism to pipes of different diameters as hereinafter described. The grooved work engaging segment I3 should also be of rigid and durable construction, and since the grooved surface I5 is formed concentric with the axis of the segment fulcrum or suspension pin I4, this surface I5 as well as the adjacent anges I6 can be readily dressed or nnished with utmost accuracy on a lathe or boring mill.

While but one segment I3 adapted to co-opcrate with pipe of relatively small diameter and swingable on a rather short radius about the axis of the holes I2 nearest the ixed end roller I0, is shown, the pipe bending outfit of Figs. 1 and 2 should be provided with three progressively larger segments I3 having correspondingly longer radii and larger grooves at their curved surfaces I5, and these additional segments I3 should be formed for proper coaction with suitably formed followers I9 adapted to nt the larger pipes. The end of the follower I9 nearest the clamp I1, should preferably be provided with a taper I9' in order tolpermit the follower I9 to assume a position corresponding to the final slightly elliptical cross-section of the bent pipe; and when the follower I9 is to be reversed for co-operation with different size piping, a tapered surface I9' should also be provided adjacent to the groove 20. As shown, the bar 'follower I9 has opposite grooves 20, 2| adapted to co-operate with two of the interchangeable segments I3 by reversing the follower I9, and another bar follower I9 having a pipe engaging grooveof still greater curvature should be provided for co-operation with the largest of the three segments I3.

In order to interchange these three segments I3, it is only necessary to remove the fulcrum pin I4 from one set of alined holes I2, I2', I2" and from the segment I3 coacting therewith, and to insert this same pin Il within another set and parallel flanges I3 on the opposite sides of of the receiving holes and another of the segments. without disturbing the rest of the mechautant.A The bar follower Il may then be reversed so as to cause the groove 2i thereof to face the segment groove I5, or the additional bar follower (not shown) may be applied, in order to insure proper coaction of the segment I3 and follower Il with the particular size of pipe which is to be bent.

Each quadrant segment I3 has a pipe gripping element or U-shaped clamp i1 pivotally attached thereto near the corresponding ends of the 'grooved surface I5 and nanges I6 thereof. by means of a pivot bolt or pin I8; and the contour of this clamp I1 is such that a pipe 21 shown in dot-and-dash lines in Figs. 1 and 2, may be readily inserted between the surface Ill and follower Il within the clamp, before the segment I3 is engaged by the ram piston 25. However, when the segment I3 is swung about its fulcrum pin I4 in a clockwise direction as viewed in Fig. l, the clamp I1 will tend to swing in a counterclockwise direction about its pivot pin I8, and will thug firmly grip the pipe 21 and clamp the same into the adjacent end of the groove I5, and will thereby cause the pipe to advance with the segment I3. While the internal surface of the clamp I1 is preferably truly cylindrical, the coacting grooves I5, 29 of the segment I3 and follower I3 may be shaped to snugly nt the final slightly elliptical cross-sectional shape of the pipe 21 when bent, and in order to insure snug coaction,

'the follower I9 when in engagement with the bearing roller Ill may also be separated from the segment periphery or curved surface by spaces Each bending member or segment I3 also carries an anti-friction roller 22 disposed remote from the clamp I1 thereon, and this roller 22 is Joumalled upon a pin 23 and is adapted to ride back and forth across the plane face 2B of the ram piston 2l when the segment I3 is being swung about the fulcrum pin I4 by the ram plunger. The cylinder 24 of the actuating ram is adapted to be detachably secured to the threaded socket 9 of the rigid frame 8; and the piston 2l which is movable within the cylinder 24 by hydraulic pressure created by a pump communicating with the cylinder through a ilexible conduit, is adapted to be withdrawn from contact with the roller 22 in order to permit interchangeable application of the several segments I3 of diilerent sizes to the frame 8.

During normal operation of the pipe bending unit shown in Figs. l and 2, the hydraulic ram should first be manipulated to withdraw the piston 25 slightly from the roller 22, and the piece of small diameter tube or pipe 21 should be a-pplied to the segment I3 and clamp I1 as indicated in Fig. l with the rectilinear bar follower I9 positioned as shown. The ram should then be actuated to cause the piston 25 to engage and move the roller 22 toward the bearing roller I0, whereupon the clamp I1 will rmly grip the adjacent portion of the pipe 21 and will cause the pipe to advance with the revolving segment I3. As the piston '25 continues its outward movement, the segment I3 continues to revolve and the bar follower I9 will then be advanced with the segment I3 and along the roller III. This simultaneous advancement of the segment I3, follower I9 and pipe 21 will cause the pipe to be bent around and along the arcuate groove I5 of the segment Il while being slightly distorted into the elliptical cross-sectional shape shown in Fig.

bending operation has been completed. the inove` ment of the ram piston it may be reversed, and the segment it and ber follower it may thereafter be returned to the position shown and the bent pipe y be withdrawn from the la il. It it is desired to d pipe t? of .n er diameter and to a larger radius of curvature, the segment it may be quickly replaced by a larger segment with the fulc pin it disposed in either set of holes l2', is", and the follower it may also be reversed or replaced by another having a groove properly shaped to fit the larger pipe.

le the follower l@ of Figs. 1 and 2 is of the rectilinear bar-type, this follower may also be replaced by a rotary follower 2t such as shown in Fig. 3. The rotary follower' it has a peripheral groove til formed to fit the final shape of the pipe 'it after bending thereof, and is iouimalled on a transverse pin lll which may be substituted for the pin il of Fig. 1. The periphery of the rotary follower 2d may also be separated from the periphery of the segment i3 by spaces 2d, as in the case of the follow bar, and this .modiiied assemblage will operate in a manner similarvto that of the device shown in Figs. 1 and 2. During the bending operation, the rotary follower 2li will revolve upon the pin. 3i in a direction opposite to the direction of revolution oi the segment i8, and the follower di? will constantly 'retain the pipe ill in snug engagement with the grooved surface it oi the segment it.

Referring specifically to the modified pipe bender shown in Figs. d and 5, this unit is quite similar to that shown in Figs. l and 2 except for various detalls of construction of the -mechanism. In order to obtain better application of the pressures and distribution of the stresses when bendingV pipes 2li of dierent sizes, the main frame 35i oi' the modified assemblage has been formed to position the bearing rollel` it out of the line oi movement of the ram piston 2li; and the sets of holes l2, lli', i2" for interchangeably receiving the fulcrum pin ld of the modified segment dii, have been 1re-enforced by plates 3d punched from openings d@ in-I the opposite side walls of the frame 3E and welded to these walls adjacent to the holes. The modiiied segments 83 have also Vbeen additionally re-enforced, and while the pipe clamp il is the same as previously described, the anti-,friction roller 2i has been located with reference to the fulcrum pin ld so that this roller will travel nearer to the central axis of the actuating plunger 2b when the bending operation is being completed and maximum force is being applied. The rectilinear bar follower t of the modified structure is provided with but a single pipe engaging recess 3i which is co-operable with the peripheral curved pipe confining recess dd of the segment 3i. and the modified bending outfit should again be provided with three independent segments dei and bar followers 13b of different sizes, adapted to coact with diiierent sizes of pipes. which rotatably supports the follower engaging roller il) of the modified structure. is of special construction, and this modified -pin di has an integral centra-l eccentric d2 and an integral serrated portiond adjacent to one'end of the eccentric d, which is rotatably adjustable within l The journal pin il s removable M having a serrated hole formed 4centrally therein. Upon' release of the clamping nuts 4B at the opposi mds of the pin 4l and which normally clamp this pin in odiusted position, the pin may M shiftedlto the left as viewed in Fig. E, 1li iently to release the serrated portion it. land su tly revolved to'cause the eccentric di to move the roller It toward or away from the ent it, thus mah- ,ing it possible to cause the single roller ld to properly co-operate with the followers di and segments dit at'all times. The pins di, It are readily removable to rele the roller it and the segments Si respectively, by merely removing theretaining nuts. The operation oi the modi lied pipe bender of Figs. d and 5 is obviously the jsame as that of Figs. l and 2. and both benders are adapted for use in bending pipes of three .different diameters.

In Fig. 6, I have shown a modided rotary iollower itv which may be utilized in substitution for the followers it, 2li, lid of the previously decori pipe benders. The erdble or resilient cylindrical follower d@ is conned between metal side plat it and is iournalled for rotation in the frame d2 by means of a transverse pin li i, and this follower @d may be formed of relatively hard but resilient rubber or the like. The periphery oi this roller follower et is normally cylindrical or apprend-f mately so, but when the follower @t engages a pipe El to force the same into the sent groove 3d, it will distort to the shape of the adjacent contour of the pipe 2l without indenting the latter. "l type of follower dit will au mtically distort to snugly dt any size of pipe 2l and need not be replaced when the segments are inter changed; and the side plates d@ and hangers id of the segments itil will aid in' causing the distorted portion of the follower @d to hug the pipe di.

From the foregoing detailed description of the construction and operation of my improved pipe bending unit, it will be apparent that the invenu tion provides a pipe bender which is extremely simple and compact in construction and which is highly emcient in actual use. The improved mechanism comprises a relatively few simple and durable parts which can be readily manufactured and assembled, and the improved structure can be readilyinterchanged so as to properly coast with pipes having dierent diameters. The use of the rotary followers 2d, il@ additionally simplifies the assemblage and reduces the bulk thereof, and the use of the ilegible or resilient follower i3d of Fig. 6 further reduces the number of parte necessary in order to adapt the bender to pipes of diierent sizes, to a minimum. The modified eccentric pin di of Figs. e and 5, also makes it possible to adjust the reaction roller l@ so as to insure proper coaction between the follower and the bending segment. The modified assemblage of Figs. s and 5 also has the advantage of permitting convenient bending of the pipes di through longer distances than is possible with the embodiment of Figs. l and 2. With the structure of Figs. d and 5, pipes can readily be bent through arcs greater than ninety degrees when either large or small segments il@ are used, and the angular disposition of the frame with respect to the ram combined with the location of the axes of the holes i2, i2', i2" in a common plane with the axis of the pin di facilitates such long bending. The entire pipe bending mechanism can be associated with a standard ram of the portable type, operable from a remote point with the aid of a pump connected to the ram by nexible' conduits, and the structurel is adapted to produce successive bends of uniform radius and without undesirably distorting the cross-section areas of the pipes. 'I'henew pipe bender'can be manufactured and sold at relatively moderate cost, and has proven highly` successful in actual use. While the elliptical shape of the coacting grooves is relatively unimportant, the initial tapering of the bar followers is vitally important.

It should be understood that it is not desired to limit this invention to the exact details of construction, or to the precise mode of use, herein shown and described, for various modifications with the scope of the appended claims may occur to persons skilled in the art.

Iclaim:

l. In combination, a rigid frame having a transverse pivot pin mounted thereon, a segment swingable upon said pin and having a curved pipe engaging surface formed concentric with the pivot pin axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending of the pipe, means for causing the pipe to positively advance about said axis with said segment, and a hydraulic ram having a piston provided with an end surface abutting loosely against and slidably co-operable with said segment, said piston being movable toward the segment at a point between said axis and said pipe engaging surface to swing the segment about said pin,

2. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum and having a curved pipe engaging surface formed concentric with the fulcrum axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending of the pipe, means for positively causing the pipe to advance about said axis with said segment, and a reciprocable plunger member movable with respect to said frame toward said segment at a point between said axis and said pipe engaging surface to swing the segment about said fulcrum, said member having a. transverse end surface loosely abutting against and slidably coacting with said segment.

3. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum and having a curved pipe engaging surface formed concentric with the fulcrum axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending of the pipe, means for positively causing the pipe to advance about said axis with said segment, a reciprocable plunger member movable with respect 'to said-frame toward said segment at a point between said axis and said pipe engaging surface to swing the segment about said fulcrum, said member having a transverse end surface loosely abutting against and slidably coacting with said segment, and a roller carried by said segment and coacting with said member surface to provide an anti-friction bearing at the zone of said sliding coaction.

4. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum and having a curved pipe engaging surface formed concentric with the fulcrum axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending ofthe pipe, a clamp carried by said segment at one end of said curved surface and being engageable with the pipe near the corresponding end of said follower to positively cause the pipe to advance about said axis with the segment, and a reciprocable plunger member movable upon said frame toward said segment at a point between said axis and said pipe engaging surface to swing the segment about said fulcrum, said member having a transverse plane end surface loosely abutting against and slidably coacting with said segment.

5. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum, and having a curved pipe engaging surface formed concentric with the fulcrum axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending of the pipe, a clamp carried by said segment at one end of said curved surface and being engageable with the pipe near the corresponding end of said follower 4to positively cause the pipe to advance about said axis with the segment, a reciproc'able plunger member movable upon said frameioward said segment at a point between said axis and said pipe engaging surface to swing the segment about said fulcrum, said member having a transverse plane end surface loosely abutting against and slidabiy coacting with said segment, and a hydraulic cylinder carried by said frame and within which said plunger member is movable by fluid pressure.

6. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum 'and having a curved pipe engaging groove formed concentric with the fulcrum axis, a follower having a rectilinear pipe engaging groove adapted to retain the pipe in contact with said segment groove during bending of the pipe, means for positively causing the pipe to advance about said axis within said grooves, and a reciprocable plunger member movable upon said frame toward said segment at a point between said axis and said pipe engaging groove to swing the segment about said fulcrum, said member having a, transverse end surface loosely abutting against and slidably coacting with said segment.

7. In combination, a rigid frame having a transverse fulcrum thereon, a segment swingable about said fulcrum and having a curved pipe engaging groove formed concentric with the fulcrum axis, a follower having a rectilinear pipe engaging groove adapted to retain the pipe in contact with said segment groove during bending of the pipe, means for positively causing the pipe to advance about said axis within said grooves, and a reciprocable plunger member movable upon said frame toward said segment at a point between said axis and said pipe engaging groove to swing the segment about said fulcrum, said member having a transverse end surface loosely abutting against and slidably coacting with said segment, and the end of said follower nearest said means being gradually longitudinally tapered to cause the follower to be urged toward the segment groove as the pipe bending operation proceeds.

8. In combination, a rigid frame member having a transverse pivot pin mounted thereon, a segment swingable upon said pin and having a curved pipe engaging surface formed concentric with the pivot pin axis, a pipe engaging follower adapted to retain the pipe in contact with said segment surface during bending of the pipe, clamping means for causing the pipe to positively advance about said axis with said segment, a ram having a piston provided with an end surface loosely engaging and slidably cooperable with said segmenti said piston being movable toward the segment ata point between said axis and said pipe engaging surface to swing the segment about said pin, and means for effecting adjustment of said pin relative t0 said rigid frame in order to accommodate segments having different radii.

9. In combination, a rigid frame having thereon a fixed fulcrum and a reaction element spaced from the fulcrum, a rigid segment swingable upon said fulcrum and having an arcuate pipe engaging groove remote from the fulcrum movable past said element about said i'ulcrum vrelative to said frame, a pipe clamp carried by said segment for advancing a pipe coacting with said groove about said fulcrum and past said element, and an elongated follower constantly movable with said Segment past said reaction element and being progressively engageable with successive portions of the pipe and segment groove, lthe end of said constantly advancing follower nearest said clamp being gradually tapered in the direction of movement thereof and the tapered portion being movable past and in contact with said element to cause the constantly advancingfollower to approach the segment groove as the pipe bending operation proceeds.

10. In combinationfa rigid frame having thereon a xed fulcrum and a reaction roller spaced l from the fulcrum, a rigid segment swingable upon said fulcrum and having an arcuate pipe engag- :ing groove remote from the fulcrum movable past said roller, means for swinging said segment about said fulcrum relative to said frame, a pipe clamp carried by said segment for advancing a pipe co- .acting with said groove about said fulcrum and past said roller, and an elongated follower confvancing follower to approach the segment groove 20 as the pipe bending operation proceeds.

SIEGMU ND MANDL. 

